Pulse tools, i.e. power tools comprising a torque impulse generator, are e.g. used to tighten joints during an assembly operation. Such torque impulse generators comprise a rotational input portion, a torque output portion, an oil reservoir and a torque generating arrangement converting rotation of the input portion to torque impulses at the torque output portion.
In U.S. Pat. No. 5,092,410 A, EP 0885693 B1 and WO 2011141205 A1 various types of torque impulse generators are shown.
The performance of a torque impulse generator is dependent on the level of oil in the oil reservoir. Due to leakage, the level of oil in the oil reservoir tends to decrease over time. When the oil level decreases, the ability of the torque impulse generator to generate torque will decrease. If the operator of the tool is unable to recognize this there is a risk of faulty tightening and destruction of mechanical parts of the torque impulse generator.
Hence, there is a need for a simple way of diagnosing the torque impulse generator and indicating the level of oil in the oil reservoir.